Welded join



M. B WETMQRE WELDED 'JOINT Filed 3111522, l192.@

Patented Dec. 18, 1923.

UNITED STAT-Els MINER P. WETMORE, '0F NEWARK, NEW JERVSEAY, ASSIGNOR T0 HYGRADE ENGINEER- ING Cp., INC., A. CORPORATION OF NEW JERSEY.

Y WELDED JOIN;

Application led June 22, 1920. Serial No. 390,936.

To all -wwm t may concern.' Be it known that I, MINER P. Wnmonn, a citizen`of the United States of America, residing at Newark, county of Essex, State of New Jersey, have invented certain new and useful Improvements in Welded Joints, of which the following is a specification.

My invention relates to electric welding and comprises a special form'of electrically welded joint between a wire and a 4tube which is particularly easy of formation requires a relatively small amount of lelectric current and mechanical force for the weld'` ing operation and is also particularly strong 16 and ofgood electrical conductivity. The

best form of structure embodying my invention at present known to me is illustrated in the accompanying sheet lof drawings in l V 20 Fig. 1- is a perspective-view of sections of wire and tube-welded together to form my invention. y l

Fig. 2 is a longitudinal section of the same on an enlarged scale, parts being broken away, and

Fig. 3 is a cross section 'on| an enlarged scale taken on line 3 3 of Fig. 1. Throughout the drawings like reference characters indicate like parts. The embodiment of the invention here illustrated may -most conveniently be made by the welding apparatus shown andde# scribed in my copending .application Serial No. 377487, led April 29, 1920, allowed 85 June 3, 1920. It comprises a tube 1 partway telescopedover'a section of wire 2, the

diameter ofwhich wire is slightly less than the internal diameter of the tube, and then partly flattened down on the wire by the o pressure of a pair of electrodes between which the joint is grasped, the tube and portion of the wire enclosed therein, which is also slightly flattened, as shown, having been both softened by the passage of a welding current of electricity passing through them from one electrode to the other and welded together along the meeting flattened surfaces to form the joint 3.

In thus making this joint, all Vof the curo' rent first passes through the thin walls of the'tube, quickly softening it so that it collapses on the enclosed wire without requiring the exertion of much pressure b the electrodes. The contacts so first estab ished between the opposite attened portions of the tube wall and the cylindrical body of the enclosed wire exist only along narrow lines parallel to the axis of the wire. Conwalls which have been heated by the initial o5 passage of current through them is veasily broug t to a proper condition for welding 9 by the additional heat generated byz the y portion ofthe current which passes through it as soon as the tube walls are collapsed l70 I. yupon it. As a result, the portions of the cylindical wire surface in contact with the collapsed tube walls are rapidly heatedeand softened and easily flattened bythe pressure of the electrodesA so that the wire and tube are welded together throughout substantial areas of their opposing surfaces, as shown in Fig. 3, formin a'mechanically strong joint and-one also aving high electrical conductivity. 8o

My invention is particularly useful for filament supports and connections in incandescent electric lamps. In such case 'the cylindrical portion of tube 1 serves as a cup for receiving the 'endof the filament and 8,5 the partially collapsed portion of the tube,

.whenfused into the glass of the lamp together with a portion of wire 3, forms a particularl iirrn anchorage therefor and one not lia le to crack the glass by expanl sion, as -the hollow spaces 4, 4, leftbetween tube4 and wire permit the tube, which is ./f'

usually made of nickel, to yield by bending or further collapsingbefore exerting force enough to crack the surrounding glass. The es l* wire 1 is usually made of platinum 'or of f some composite structure which has thev g3 same coeiiicient of expansion under heat as; "E glass has. The advantages of the invention therefore?! 100 comprise not only the useful qualities of thef completed article itself, but also the savi ing of time, mechanical power, and elec-v trical currentvconsumed in its manufacture.

Having liescribedmy invention' Icleim:V ti0ns-oflthe wire and tube surfaces are left 4 As an article of manufacture an e1ectrica1 separate each from the other.

. and mechanical connector comprising a section of wlre over and Aonto which a section 6 o tubing'of-somewhat'larger diameter has been fiattened, the meeting surfaces being welded together while the remaining por:

MINER P. WETMORE. Witnesses: i' l CLIFFORD TITCHEN. ROBT. VAN BBUNT. 

